Tsunami bomb feasible, secret WWII test showed

Jonathan Pearlman

THE US and New Zealand conducted secret tests in the 1940s of a ''tsunami bomb'' designed to destroy coastal cities by using underwater explosions to trigger tidal waves.

The tests were carried out in waters around New Caledonia and Auckland during World War II and showed the weapon was feasible. A series of 10 large offshore blasts could potentially create a 10-metre tsunami capable of inundating a small city.

The top-secret operation, ''Project Seal'', tested the doomsday device as a possible rival to the nuclear bomb. About 3700 bombs were exploded during the tests in New Caledonia and on Whangaparaoa Peninsula, near Auckland.

The plans came to light during research by a New Zealand author and filmmaker, Ray Waru, who examined military files buried in the national archives.

''It was absolutely astonishing,'' Waru said, ''first that anyone would come up with the idea of developing a weapon of mass destruction based on a tsunami … and also that New Zealand seems to have successfully developed it to the degree that it might have worked.''

Waru said initial tests were positive but the project was shelved in early 1945.

Experts concluded that a successful tsunami bomb would require about 2 million kilograms of explosive arrayed in a line about 8 kilometres offshore.